Michael de Podesta has been doing the math on "Grime Dice" — six sided cubes whose sides average out to 3.5, but whose face values are all radically different:
The interesting thing about these is that the odds of one die beating another are simple to calculate, but shift radically once you start rolling dice in pairs. It's a beautiful piece of counterintuitive probability math:
The amazing property of these dice is discernible when you use them competitively – i.e. you roll one dice against another. If you roll each of them against a normal dice then as you might expect, each dice will win as often as it will lose. But if you roll them against each other something amazing happens.
- Dice A will systematically beat Dice B
- Dice B will systematically beat Dice C
- Dice C will systematically beat Dice A
So the fact that Dice A beats Dice B, and Dice B beats Dice C does not ensure that Dice A will beat Dice C. Wow!
And how about this: If you 'double up' and roll 2 Dice A's against 2 Dice B's – the odds change around and now the B's will beat the A's ! Is that really possible? Well yes, and just to convince myself I wrote a Spreadsheet (.xlsx file) and generated the tables at the bottom of the article. If you download it you can change the numbers to try out other combinations.
Amazing Dice: Rediscovering surprise
(via Hacker News)